Package org.axonframework.messaging.queryhandling.interception

Class InterceptingQueryHandlingComponent

java.lang.Object
org.axonframework.messaging.queryhandling.interception.InterceptingQueryHandlingComponent
All Implemented Interfaces:
DescribableComponent, MessageHandler, QueryHandler, QueryHandlingComponent
@Internal public class InterceptingQueryHandlingComponent extends Object implements QueryHandlingComponent
A QueryHandlingComponent that applies a list of interceptors around every query before delegating to the underlying component.

Interceptors are invoked in registration order. Each interceptor can inspect the query, modify it, short-circuit handling, or proceed to the next interceptor in the chain.

Since:
5.2.0
Author:
Allard Buijze

  • Constructor Details

    • InterceptingQueryHandlingComponent

      public InterceptingQueryHandlingComponent(List<MessageHandlerInterceptor<? super QueryMessage>> interceptors, QueryHandlingComponent delegate)
      Constructs a new InterceptingQueryHandlingComponent wrapping the given delegate with the given interceptors.
      Parameters:
      interceptors - the interceptors to apply, in invocation order
      delegate - the underlying component to delegate to after all interceptors have proceeded

  • Method Details

    • handle

      public MessageStream<QueryResponseMessage> handle(QueryMessage query, ProcessingContext processingContext)
      Description copied from interface: QueryHandler
      Handles the given query within the given context.

      The resulting stream may contain zero, one, or N response messages.

      Specified by:
      handle in interface QueryHandler
      Parameters:
      query - The query to handle.
      processingContext - The context to the given command is handled in.
      Returns:
      A MessagesStream of zero, one, or N response messages.

    • supportedQueries

      public Set<QualifiedName> supportedQueries()
      Description copied from interface: QueryHandlingComponent
      All supported queries, referenced through a QualifiedName.
      Specified by:
      supportedQueries in interface QueryHandlingComponent
      Returns:
      All supported queries, referenced through a QualifiedName.

    • describeTo

      public void describeTo(ComponentDescriptor descriptor)
      Description copied from interface: DescribableComponent
      Describe the properties of this DescribableComponent with the given descriptor.

      Components should call the appropriate describeProperty methods on the descriptor to register their properties. The descriptor is responsible for determining how these properties are formatted and structured in the final output.

      Best Practices: As a general rule, all relevant fields of a DescribableComponent implementation should be described in this method. However, developers have discretion to include only the fields that make sense in the context. Not every field may be meaningful for description purposes, especially internal implementation details. Furthermore, components might want to expose different information based on their current state. The final decision on what properties to include lies with the person implementing the describeTo method, who should focus on providing information that is useful for understanding the component's configuration and state.

      Example implementation: 

       public void describeTo(ComponentDescriptor descriptor) {
     descriptor.describeProperty("name", this.name);
     descriptor.describeProperty("enabled", this.enabled);
     descriptor.describeProperty("configuration", this.configuration); // A nested component
     descriptor.describeProperty("handlers", this.eventHandlers);      // A collection
 }
      Specified by:
      describeTo in interface DescribableComponent
      Parameters:
      descriptor - The component descriptor to describe this DescribableComponentn its properties in.